Fig. 6. Reelin signals directly to radial glial cells. (A,B) FACS profiles as described in Fig. 4 of two independent sorts selectively enriching for radial glial cells. In A, GFP-negative (black fraction in the histogram) precursor cells were isolated from the Tau::EGFP-mouse mouse line containing GFP in postmitotic neurons (Tucker et al., 2001); in B, GFP-positive cells (green fraction in the histogram) were isolated from the hGFAP-GFP mouse line with GFP in radial glia (Zhuo et al., 1997; Malatesta et al., 2000). Histograms in A' and B' depict the proportion of Rc2-only or Rc2- and Blbp-immunopositive cells cultured after the sorting in control (red bars) or reelin-conditioned (blue bars) medium for 24 hours. Note the significant (Student's t-test,^*P<0.04) increase in Blbp-immunoreactive radial glia after exposure to reelin-conditioned medium, indicating that the presence of neurons is not required to mediate this effect. [Number of cell analysed: A, n(Ctrl)=237, n(Rln-med.)=354; B, n(Ctrl)=215, n(Rln-med.)=367.]